part of geology which deals with the structure of the earth's crust caused by orogenic deformations (dislocations, folds, fracturations).

Shaped like a doughnut. Of, relating to, or shaped like a torus or toroid: doughnut shaped. A toroid is an annular shape generated by revolving a circle around an axis external to the circle.

during the formation of the solar system, grains agglomerated in planetesimals, intermediate state before the final formation of the planets.

equipotential surface which (approximately) coincides with the mean ocean surface. It is often referred to as a close representation or physical model of the figure of the Earth. It is that equipotential surface (surface of fixed potential value) which coincides on average with mean sea level.

matter projected during volcanic eruptions.

a couple of stars composed of one giant and one super-dense i.e. neutron star or black hole. The outer layers of the giant or supergiant star accumulate around the dense object until there is enough for a sudden X-ray "explosion".

The Wavelength of the water ripples created by a rock falling is the distance between two consecutive peaks. It is the same for electromagnetic waves i.e. same nature than light. The wavelength of such waves is associated with the frequency, the colour or the energy: from lowest energies with radio waves (large wavelength, superior to a millimetre) [..]

(part of classical mechanics) states the following: Every single point mass attracts every other point mass by a force pointing along the line combining the two. The force is proportional to the product of the two masses and inversely proportional to the square of the distance between the point masses: F = G · m1 · m2 / r²

by using the different times measurement of different satellites observing the same event (such as a gamma burst), as well as the position of these satellites around the Earth at the moment of the measurement, the direction of the emitting source can be determined. This method is based on the same principle than the triangulation measurements used [..]

The tide phenomenon turns up each time two celestial bodies - planets, galaxies... - have sufficient mass and are sufficiently near to be gravitationally attracted one by the other. The resulting force, force generating the tide, can participate to the deformation of a portion of the body considered, at least if this portion is effectively composed [..]